The present invention is concerned with a method for the marking of documents, which is intended to avoid confusion of copies with originals.
At any time one finds oneself confronted with the need of reproducing documents and not so very long ago numerous documents were drawn up in a number of copies printed by means of carbon paper. The appearance on the market of photocopiers has confused the data of this problems to the extent that it has become possible to reproduce a finished document with practically the same quality as the original.
Whereas with the black/white photocopiers first available on the market an original was distinguished without difficulty from a copy because on the one hand of the quality of the copy and on the other hand of the quality of the paper to be utilised for the photocopy, the development of the technique has enabled documents to be reproduced on practically any kind of backing paper with a nearly perfect quality.
However, in the case of black/white photocopiers it always remained possible to distinguish the original from the copy when the original was in colour.
Now, the availability of photocopiers which enable colours to be reproduced has again marked important technical progress. At the start, as had been the case for black/white copiers, very special paper had to be utilised for the reproduction of the colours. Today, however, the latest technique enables backing paper of no matter what kind to be utilised. Thus it has become extremely difficult to distinguish an original from a good-quality copy since on the one hand the drawings and colours are reproduced with great fidelity and on the other hand the very nature of the paper can no longer serve as a criterion of the distinction between an original and a copy.
Technicians and users are obviously pleased with this new quality in the industry of graphic reproduction. This very technical quality is, however, dangerous when its exploitation is employed with an illicit or dishonest aim.
In the first place one certainly thinks of bank notes which may be reproduced in colours on paper presenting a grain which may obviously be confused with the original grain of the money paper. The falsification of documents by photocopies touches yet again, however, upon a much vaster field of documents. It is enough to think about all the securities and the whole of the documents which give a right to the delivery of an allowance, in whatever form this may be.
Consequently it has been possible to see an increasing number of attempts at falsifications, which are the more difficult to detect, the greater the progress made in the technique of reproduction.
As a consequence of this development the relatively complicated character of the graphical features of certificates of securities, stocks, as well as notes, which was the main guarantee of their originality, no longer or practically no longer assumes this function since it becomes ever more easy for anyone to reproduce them if ever he disregards his scruples.
Now, in order not to modify the fundamental rules of commerce an extremely great interest exists in being able in spite of the existence of the most highly perfected photocopiers, to continue to employ trustworthy original documents without permanently having afterthoughts as to their original character or not.